Applying the uniform resampling (URS) algorithm to a Lissajous trajectory:Fast image reconstruction with optimal gridding

Various kinds of nonrectilinear Cartesian k-space trajectories have been st udied, such as spiral, circular, and rosette trajectories. Although the non rectilinear Cartesian sampling techniques generally have the advantage of f ast data acquisition, the gridding process prior to PD-FFT image reconstruc tion usually requires a number of additional calculations, thus necessitati ng an increase in the computation time. Further, the reconstructed image of ten exhibits artifacts resulting from both the k-space sampling pattern and the gridding procedure. To date, it has been demonstrated in only a few st udies that the special geometric sampling patterns of certain specific traj ectories facilitate fast image reconstruction, in other words, the inherent link among the trajectory, the sampling scheme, and the associated complex ity of the regridding/reconstruction process has been investigated to only a limited extent. In this study, it is demonstrated that a Lissajous trajec tory has the special geometric characteristics necessary for rapid reconstr uction of nonrectilinear Cartesian k-space trajectories with constant sampl ing time intervals. Because of the applicability of a uniform resampling (U RS) algorithm, a high-quality reconstructed image is obtained in a short re construction time when compared to other gridding algorithms. (C) 2000 Wile y-Liss, Inc.